1. Field of the Invention
The invention relates to compositions for improving the appearance of skin, particularly to provide good coverage over imperfections such as pores and uneven skin tone, while retaining a natural skin appearance.
2. The Related Art
A matte effect is desired for users of color cosmetics. The matte finish overcomes the shiny effect engendered by greasy skin, particularly under hot and humid conditions. Absorbent fillers such as talc, silica, kaolin and other inorganic particulates have been used to achieve the effect by their optical properties.
Imperfect skin can be hidden in two ways through manipulation of light transmission. In the first, components of the color cosmetic may simply reflect light back toward the source. An alternative approach is referred to as achieving a soft focus effect. Here the incoming light is distorted by scattering (lensing). Components of the color cosmetic in this mechanism operate as lenses to bend and twist light into a variety of directions.
While it is desirable to hide imperfect skin through a matte effect, there is also a desire to achieve a healthy skin radiance. A cosmetic covering that is too opaque hides the skin under a paint-like coating. Imperfections are hidden but there is no radiance. Where light transmission is insufficiently hindered, the opposite occurs. Here the glow may be healthy but aesthetically displeasing skin topography and color may now be apparent.
U.S. Pat. No. 5,997,890 (Sine et al.), U.S. Pat. No. 5,972,359 (Sine et al.), and U.S. Pat. No. 6,174,533 B1 (SaNogueira, Jr.) are all directed to topical compositions to provide good coverage of skin imperfections. The solution proposed by these documents is the use of a metal oxide with a refractive index of at least about 2 and a neat primary particle size of from about 100 to about 300 nm. Preferred particulates are titanium dioxide, zirconium oxide and zinc oxide.
Silicone gelling agents such as crosslinked organopolysiloxane elastomers because of their excellent skinfeel properties have been found useful in make-up compositions. For instance, U.S. Pat. No. 5,266,321 (Shukuzaki et al.) discloses an oily make-up composition comprised of a silicone gel crosslinked elastomer, titanium dioxide, mica and iron oxides. Japanese patent application 61-194009 (Harashima) describes a make-up composition comprising a cured organopolysiloxane elastomer powder and pigments which may be selected from talc, titanium dioxide, zinc oxide and iron oxides.
A challenge which has not been fully met by the known art is delivery of a composition with appropriate optics to achieve both soft focus and radiance properties in a system that still provides excellent skinfeel.